Alaska Sea Otter Expedition Seeks Clues to Coastal Health

Alaska Sea Otter Expedition Seeks Clues to Coastal Health

JUNEAU, Alaska, May 24, 2011 (ENS) – Marine biologists from the United States and Canada are on a three-week expedition studying sea otters to document the ecological health of the Pacific coastline.

The Pacific Nearshore Project is a multi-national, multi-agency project investigating sea otters as health indicators of coastal waters and marine resources from California north through Canada and Alaska.

Sixteen researchers from four research institutions will sail between Juneau and Ketchikan, capturing sea otters for physical exams, biopsies, and blood tests, observing sea otter feeding behavior, and collecting samples from fish and other species that hold clues to the ecological health of the coast.

“Sea otters are the perfect health indicators of our nearshore waters,” says James Bodkin, a U.S. Geological Survey research biologist and the project’s chief scientist. “They’re entirely dependent on nearshore marine habitats and they are keystone species in kelp forest food webs.”

A pair of sea otters in Alaska (Photo by R. Davis, TAMU courtesy IUCN Otter Specialist Group)

“Some populations are abundant and stable, while others are either declining or struggling to reach healthy numbers,” said Bodkin. “Can these differences be explained by ocean influences, or by human impacts to the adjacent watersheds? That’s what we’re hoping to learn.”

Sea otters are an apex predator of the nearshore ecosystem, at the center of the local food web. Sunlight and nutrients are absorbed by tiny algae and giant kelp, and these plants are eaten by shellfish, which in turn are eaten by otters.

Any contamination or damage to even the most distant links of the food web could have an impact on otters’ health, demonstrating problems in the ecosystem.

Sea otters in southwest Alaska are classed as threatened. In October 2009, the U.S. Fish and Wildlife Service designated 5,855 square miles of nearshore waters along the Aleutian Islands, Bering Sea, and Alaska Peninsula as critical habitat for the northern sea otter.

Fewer than 40,000 otters were estimated to exist in southwestern Alaska in 2005, down from more than 100,000 in the 1970s. Declines are most pronounced in the Aleutian Islands, where the population has dropped from more than 70,000 to fewer than 10,000 animals.

The Alaska expedition is among the last of several sampling missions that began in 2008 at locations including Big Sur in California and the Katmai coast of Alaska.

In the next two years, project researchers will utilize information from DNA analysis, disease and toxin studies, sea otter diets, fish growth rates, and satellite imagery to assess and compare the health of some of North America’s most iconic coastlines.

“It’s not so much ‘CSI: Sea Otters’ as it is ‘CSI: Coastal Health,'” says Seth Newsome, referring to the TV show “Crime Scene Investigation.”

The University of Wyoming researcher will analyze the chemical signature of otter whiskers and fish muscle tissue collected from the expedition. “Sea otter health and diet tells us a great deal about the quality of their marine habitat – the same habitat that supports our fisheries and our recreational waters.”

Taking whiskers from wild otters could be tough, but the captured animals will be sedated during the biopsies. “We actually use the same anesthetics that doctors use for colonoscopy exams in humans,” says Dr. Mike Murray, chief veterinarian at the Monterey Bay Aquarium. Murray is the expedition’s veterinarian, operating a mobile otter examination clinic on the research vessel’s deck.

USGS ecologist Keith Miles, a co-leader in the project, said, “We have colleagues who are using groundbreaking techniques to solve this mystery, including a blood test that can show whether an otter has been exposed to oil, parasites or other types of stress.”

“This is an extraordinary collaboration among government agencies, research institutes and universities working together to understand our coastal resources. We’ll all be learning something new.”

The expedition will wrap during the week of June 6, and expedition photos will be made available throughout the summer.

The project is led by the U.S. Geological Survey with research partners from the Monterey Bay Aquarium, Department of Fisheries and Oceans Canada, National Park Service, U.S. Fish and Wildlife Service, Seattle Aquarium, University of California, University of Idaho, University of Wyoming and California Department of Fish and Game.

Copyright Environment News Service (ENS) 2011. All rights reserved.

Continue Reading